Vacuum cleaners which utilise cyclonic separators are known. In a typical cyclonic vacuum cleaner, an airflow in which dirt and dust is entrained enters a first cyclonic separator via a tangential inlet which causes the airflow to follow a spiral or helical path within a collecting chamber. This causes dirt and dust to be separated from the airflow. Relatively clean air passes out of the chamber while the separated dirt and dust is collected therein. In some appliances, the airflow is then passed to a second cyclonic separator stage which is capable of separating finer dirt and dust than the first cyclonic separator. This fine dirt and dust is typically also collected in the collecting chamber. The cleaned airflow then exits the collecting chamber.
The absence of a bag in a cyclonic vacuum cleaner can create difficulties for the disposal of the dirt and dust which is collected by the cleaner. When the collecting chamber of a cyclonic vacuum cleaner becomes full, a user typically removes the collecting chamber from the main body of the machine and tips the collecting chamber upside down. Often it may be necessary for the user to dislodge the dirt manually, which can be inconvenient.
An improved separating apparatus is disclosed in EP 1370172 and is shown in FIGS. 1a and 1b. The separating apparatus 1 comprises a separator 2 and a collecting chamber 3. In the illustrated separator 2, airflow passes through a first separation stage 4 and then a second separation stage 5 which comprises a set of tapered cyclonic chambers arranged in parallel with one another. Dirt which is separated by the first 4 and second 5 cyclonic stages collects at the bottom of the chamber 3, against its base 6. The base 6 is pivotably attached, by means of a hinge, to the cylindrical wall that makes up the sides of the chamber 3. The base 6 is held firmly closed by means of a first catch 7, which is operable by the user by means of a trigger 8. When the user operates the trigger 8, the base 6 swings open and the material in the collector falls out of the collecting chamber 3.
It is also useful to be able to remove the collecting chamber 3 from the separator 2. To this end, a second catch 9 is provided. When the user operates the second catch 9, the collecting chamber 3 and separator 2 may be disengaged from each other so that the user may, for example, clear large blockages from the separating apparatus or clean the interior of the collecting chamber.
A problem which may be encountered with this type of arrangement is that the user may inadvertently operate the wrong catch. For example, the user may operate the second catch 9 instead of the first catch 7 so that, even though the user intends only to open the base of the collecting chamber for emptying, the entire collecting chamber may come away from the separator. This can be frustrating and confusing for the user and may result in dirt and dust spilling out of the collecting chamber. It is desirable that the user is able to empty the collecting chamber in an efficient and hygienic manner.